DFliyerz
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Cleaning Aluminum Chloride
One of my favorite Erlenmeyer flasks has a ton of aluminum chloride hexahydrate residue which I think has polymerized, and I can't get it out. Any
suggestions?
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UC235
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A hydrated salt can't polymerize. But you may have basic aluminum chloride or alumina which won't be soluble in water. Have you tried using
(preferably) strong HCl or possibly NaOH solution to remove it?
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DFliyerz
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Hmm, it might actually be alumina since I neutralized the solution of aluminum chloride with sodium carbonate, and the aluminum carbonate would
decompose to alumina. Also, were you on the ##chemistry FreeNode channel? 
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Molecular Manipulations
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It's probably hydroxide, which is formed from addition of carbonates to soluble aluminum (III) ions. It's interesting that the carbonate ion is a
strong enough base to precipitate aluminum hydroxide.
-The manipulator
We are all here on earth to help others; what on earth the others are here for I don't know. -W. H. Auden
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macckone
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Sodium hydroxide will dissolve the alumina but it will damage the glass. I am not sure there is a good way to get alumina out of a flask if it
bonded. Alumina has a stronger bond to oxygen than silica, so anything that will attack alumina will also attack silica.
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DFliyerz
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I think I'll use 31.45% HCl to try and take care of it.
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macckone
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Here is a paper on leaching alumina from finely ground slurry:
http://www.minersoc.org/pages/Archive-CM/Volume_8/8-3-337.pd...
This is similar to what you want to do but without the finely ground
and slurry portions. Good luck but you might be better off just buying
a new flask. In theory acid will dissolve alumina but in reality it is a slow
process requiring heat and intimate contact. They state that HCl is better than sulphuric or nitric given the slurry they used.
Please let us know how HCl works on that. It would be useful to know.
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DFliyerz
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Quote: Originally posted by macckone  | Here is a paper on leaching alumina from finely ground slurry:
http://www.minersoc.org/pages/Archive-CM/Volume_8/8-3-337.pd...
This is similar to what you want to do but without the finely ground
and slurry portions. Good luck but you might be better off just buying
a new flask. In theory acid will dissolve alumina but in reality it is a slow
process requiring heat and intimate contact. They state that HCl is better than sulphuric or nitric given the slurry they used.
Please let us know how HCl works on that. It would be useful to know. |
Slow is fine with me, as long as it works. I've been leaving the flask sitting full of water for a month anyways, sooo...
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